Heat-sensitive transfer recording medium, producing method thereof and heat-sensitive transfer recording method

Abstract

The heat-sensitive transfer recording medium of the invention is such that an equilibrium moisture absorption rate at 23° C./50% of an undercoating layer containing a water-soluble polymer as a main component is about 15% or less, preferably 13% or less, and more preferably, a mean value (α) of the surface roughness (root mean square deviation Sq) of the heat-resistant lubricating layer is about 0.05-0.40 μm, a mean value (β) of the surface roughness (root mean square deviation Sq) of the heat-resistant lubricating layer after being allowed to stand for 10 minutes at 150° C. is about 0.00-0.70 μm, and a difference between the mean value (α) and the mean value (β) is about 0.00-0.30 μm.

What is claimed is: 
     
       1. A heat-sensitive transfer recording medium comprising:
 a base material, 
 a heat-resistant lubricating layer formed on one surface of the base material, 
 an undercoating layer formed on the other surface of the base material, and a dye layer formed on a surface, opposite to a surface facing to the base material, of the undercoating layer, 
 wherein the undercoating layer comprises a water-soluble polymer as a main component, and an equilibrium moisture absorption rate of the undercoating layer at a temperature of 23° C. and a humidity of 50% is about 15% or less. 
 
     
     
       2. The heat-sensitive transfer recording medium of  claim 1 , wherein the equilibrium moisture absorption rate of the undercoating layer at a temperature of 23° C. and a humidity of 50% is about 13% or less. 
     
     
       3. The heat-sensitive transfer recording medium of  claim 1 , wherein an average α of surface roughness (root-mean-square deviation Sq) of the heat-resistant lubricating layer is about 0.05-0.40 μm, an average β of surface roughness (root-mean-square deviation Sq) of the heat-resistant lubricating layer after standing under conditions of 150° C. and ten minutes is about 0.00-0.70 μm, and a difference between the average α and the average β is about 0.00-0.30 μm. 
     
     
       4. The heat-sensitive transfer recording medium of  claim 1 , wherein a dry coating amount of the undercoating layer is about 0.05-0.30 g/m 2 . 
     
     
       5. The heat-sensitive transfer recording medium of  claim 1 , wherein at least one layer on a side to be transferred of a transfer object is formed by an aqueous coating solution. 
     
     
       6. The heat-sensitive transfer recording medium of  claim 1 , wherein a total mass % of water-soluble polymers is greater than 50 mass % as a whole of the undercoating layer. 
     
     
       7. The heat-sensitive transfer recording medium of  claim 1 , wherein a total mass % of water-soluble polymers is at 80 mass % as a whole of the undercoating layer. 
     
     
       8. A method for producing a heat-sensitive transfer recording medium of a type which is used for a transfer object wherein at least one layer at a side to be transferred of the transfer object is formed with an aqueous coating solution and which includes a film-shaped or sheet-shaped base, a heat-resistant lubricating layer formed on one surface of the base, an undercoating layer formed on the other base surface opposite to the heat-resistant lubricating layer, and a dye layer formed on the undercoating layer, comprising the steps of:
 (a) coating an undercoating layer-forming solution comprising a water-soluble polymer as a main component onto a base surface opposite to the heat-resistant layer; and, 
 (b) drying the undercoating layer-forming solution in such a way that an equilibrium moisture absorption rate of the undercoating layer at a temperature of 23° C. and a humidity of 50% is about 15% or less. 
 
     
     
       9. The method of  claim 8 , wherein the undercoating layer is dried in such a way that theequilibrium moisture absorption rate at a temperature of 23° C. and a humidity of 50% is about 13% or less. 
     
     
       10. The method of  claim 8 , wherein the undercoating layer-forming solution containing the water-soluble polymer as the main component is coated onto the base surface opposite to the heat-resistant layer in such a way that a dry coating amount of the undercoating layer-forming solution is from not less than 0.05 g/m 2  to not larger than 0.30 g/m 2 , and
 wherein the undercoating layer-forming solution is subsequently dried. 
 
     
     
       11. A heat-sensitive transfer recording method, comprising the steps of:
 (a) providing a base material; 
 (b) forming a heat-resistant lubricating layer formed on one surface of the base material; 
 (c) forming an undercoating layer formed on the other surface of the base material, the undercoating layer comprising a water-soluble polymer as a main component, and with an equilibrium moisture absorption rate of the undercoating layer at a temperature of 23° C and a humidity of 50% that is about 15% or less; 
 (d) forming a dye layer formed on a surface of the undercoating layer, opposite to a surface facing to the base material, with the dye being sublimated by application of heat; and, 
 (e) transferring the dye to a transfer object with the application of heat.